This invention relates generally to golf equipment and, in particular, to golf club heads.
In order to improve the “feel” of golf clubs, especially putters, golf manufactures have frequently provided a face insert on the front face of the club head. Early golf clubs had face inserts made of cork, wood, rubber, or gutta-percha. More recent examples of golf clubs having face inserts include U.S. Pat. No. 5,575,472 to Magerman et al which discloses a putter head with a recess into which is poured a polymer resin that is cured and subsequently milled to produce the putter head. U.S. Pat. No. 5,524,331 to Pond discloses a metal club head with a cast graphite epoxy composite insert, and U.S. Pat. No. 5,458,332 to Fisher discloses a putter head having a polyurethane face insert with specific hardness and resiliency properties.
U.S. Pat. No. 5,807,190 to Krumme et al. discloses a club head in which a face insert is actually composed of many small rods arranged in a closely packed array. According to the Krumme patent, the use of individual rods to form the front face allows the properties of the front face to vary in any pattern over the impact area simply by varying the materials out of which the individual rods are made. Use of multiple materials within the array of rods would, however, render such a golf club head non-conforming since Rule 5(b) of Appendix II of the U.S. Golf Association requires that the whole of the impact area of a golf club head must be of the same material. Accordingly, what is needed is a golf club head having a face insert composed of individual rod elements in which the impact response properties of the individual rod elements can be varied without varying the material forming the rod elements.